The US health department on Friday approved the removal of the strictest "black box" warnings from the labels of three estradiol transdermal patches, the hormone therapies used to treat menopause symptoms.

Women in the United States have been struggling to find hormone replacement treatments such as estrogen patches to ease symptoms, including mood swings, hot flashes and sleep disturbances, amid surging demand.

The US Department of Health and Human Services did not immediately respond to a Reuters request seeking brand names for the patches.

The action adds to labeling changes to six menopausal hormone therapy products that the FDA in February approved to remove warnings related to cardiovascular disease, breast cancer and probable dementia The US Food and Drug Administration has been working with manufacturers since September to boost supplies of estrogen patches, but has not designated the patches as being in shortage "Estrogen patch market output has doubled over the past year, and manufacturers continue to expand capacity," said Dorothy Fink, deputy director of the National Institute of Child Health and Human Development, on a media call FDA is working expeditiously with applicants to take action on labeling changes for the remaining menopausal hormone therapy products "FDA has expedited the review and approval of 10 supplements this year to date, which are requests from manufacturers to make changes that could expand production.

Two of these requests were approved within the past week alone," said Sarah Ibrahim, deputy center director for regulatory programs at FDA's Center for Drug Evaluation and Research Reuters had previously reported that some injectable and vaginal estrogen products were also in short supply